Rotary switch



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Oct. 25, 1955 L. J. PATLA 2,721,911

ROTARY SWITCH Filed 000. 1.0. 1950 2 Sheets-Sheet 1 4 INVENTOR.

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L. J. PATLA ROTARY SWITCH Oct. 25, 1955 2 Sheets-Sheet 2 Filed Oct. 10, 1950 INVENTOR. of? %/a.

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United States Patent ROTARY SWITCH Louis J. Patla, Elmwood Park, Ill.

Application October 10, 1959, Serial No. 189,453 7 s Ciaims. (Cl. 200-11 This invention relates to a rotating switch and to a method and construction for mounting a switch contact or other electrical conductor on a supporting member, which may be electrically conducting, with the conductor extending through and insulated from the supporting member. This latter feature of the invention is particularly applicable to the mounting of contacts in a rotating switch constructed in accordance with the invention, but is not necessarily limited thereto. It is an object of the invention to provide an improved method and construction of the foregoing character.

It is another object of the invention to provide an improved rotating switch having a simple and reliable construction for accurately positioning the movable and stationary contacts relative to each other. A switch constructed in accordance with the present invention is particularly advantageous where knife switch type contacts are employed since this type of contact requires close tolerances in this respect. The invention, however, is not limited to such an application since the maintenance of close tolerances with a relatively inexpensive switch construction is desirable regardless of the type of contacts employed.

The method and construction referred to above for supporting a conductor may be employed to particular advantage in a rotating switch constructed in accordance with the invention. in such an application a large number of switch contacts may be readily mounted on a metal supporting plate and are insulated therefrom while passing through openings therein. This objective is obtained in accordance with the invention by a very simple, reliable, and economical construction.

It is another object of the invention to provide improved means for mounting a plurality of electrical con ductors on a supporting member which may be electrically conducting, the conductors extending through an opening in the supporting member and being insulated from each other and from the member.

It is another object of the invention to provide an improved method for mounting a plurality of electrical conductors on an electrically conducting plate, the con ductors extending through an opening in said plate and being insulated from each other and from the plate.

It is another object of the invention to provide an improved rotating switch in which one set of contacts is mounted on an electrically conducting plate, the contacts extending through an opening in the plate and being insulated from each other and from the plate.

The invention, together with further objects and advantages thereof, will best be understood by reference to the following description taken in connection with the accompanying drawings, and its scope will be pointed out in the appended claims.

, In the drawings in which like parts are designated by like reference numerals,

Fig. l is an elevational view of a switch constructed 'in accordance with one embodiment of the invention;

2,721,911 Patented Oct. 25, 1955 Fig. 2 is a cross-sectional view taken along the line 22 of Fig. 1;

Fig. 3 is a cross-sectional view taken along the line 33 of Fig. 1;

Fig. 4 is an enlarged cross-sectional view taken along the line 4- 4 of Fig. 2;

Fig. 5 is an enlarged partial cross-sectional view taken along the line 55 of Fig. 2;

Fig. 6 is an enlarged partial cross-sectional view taken along the line 66 of Fig. 2;

Fig. 7 is an enlarged partial perspective view showing certain portions of the switch disassembled;

Fig. 8 is a partial perspective view of a switch incorporating another embodiment of the invention; and,

Fig. 9 is a partial cross-sectional view taken along the line 9-9 of Fig. 8.

The embodiment of the switch disclosed in Figs. 1-7 is shown applied as a band switch for radio equipment such as a television receiver. More particularly, the switch is shown controlling circuits including a series of tubes 10, 11, and 12, which are mounted in respective sockets 10a, 11a and 12a, adjacent the switch. The switch comprises a bank of three elements 13, 14 and 15, each of these elements controlling the circuits incorporating one of the tubes 10, 11, and 12. The three switch elements are supported by a common framework and base and operated by a common control device, all as will be explained in detail subsequently.

Each section of the switch includes a stationary member 20 which supports stationary contacts 21 by an arrangement best seen in Figs. 2, 4, and 7. The member 20 is shown as being cup-shaped and is preferably of metal in the interest of greater strength and rigidity for reasons which will subsequently become clear. The cupshaped member 20 has an opening 22 extending therethrough and, in the preferred embodiment, pairs of slots 23, 24 and 25 extending through that member and communicating with the opening 22. A series of sheets of insulating material 26 are provided for supporting the contacts 21, each sheet being arranged to have two opposed edges 27 thereof extend through one of the pairs of slots 23, 24 or 25, the edges of the sheets being snugly engaged by the edges of the cup-shaped member defining the slots. Preferably the edges 27 of the sheet 26 which enter the slots not only fit snugly between the longitudinal edges of the slots but also snugly engage the ends of the slots. In such case, the edges of the member 20 defining the longitudinal sides of the slots prevent movement of the sheet 26 in a direction normal to the sheet while the edges of the member 20 defining the ends of the slots prevent movement of the sheet 26 circumferentially of the cup-shaped member.

In the preferred embodiment of the invention, the sheet 26 also has a pair of cars 28 extending laterally of the edges 27 and forming shoulders 29 which engage the rear surface of the member 20. This facilitates proper positioning of the sheets 26 during assembly and makes for a more solid construction. After the sheet 26 has been inserted in the slots the member 20 is deformed adjacent the edges of the slots. This deformation of the member 20, which may be in the form of punch or chisel marks 30, best seen in Figs. 2 and 6, displaces the metal forming the longitudinal edges of the slots inwardly against the surfaces of the sheet 26. This result is shown in Fig. 6 wherein it is seen that the metal forming the edges of the slot 25 has been driven into the sheet 26, thereby firmly locking the sheet in fixed position with respect to the cup-shaped member 20.

The stationary contacts 21 are secured to the surfaces of the same switch of the same switch 0 of the sheets 26 by any suitable means, such as by the -it--rotates with-respect to that-member.

- defining that opening. The particular contacts 21 shown in the drawing are of the .knife switch type, each one forming the female member of a pair of knife switch contacts, as may readily be seen in Fig. 4.

The -matingrotatable switch contacts are mounted on a rotatable sheet-like member 36 of insulating material. 'Thismember is circular'and -fits within the lip of the cup-shaped member 20 and is guided thereby as -Morespecifically, it will be noted in Figs. 4 and 7 that the cup-shaped member 20 has a -recesse'd flange portion 20a :within which the peripheral edge of 'the sheet like member -36 may ride. =It will-be-noted that as long as the sheet-like member 36 lies within this recessed flange-portion 2011,

it is prevented from -moving-radially by the peripheral wall 20b of the recessed. flange and is -prevented from moving in one direction along-the axis of the switch by the --radially extending shoulder ZGbfforniing a part of the recessed flange portion *Zfia.

Movement of the member 36in the opposite'direction along-theaxis -of-the switch is-preventedby a ring 37 "which maybe secured against the :outer lip ,of-the cupshaped member*20.:by any :suitable'meanssuch as the ears 38 which are'integral 'with"the cup-shaped member 20 and are bent overtheouteredge -of the ring37.

The movablecontacts'SS extend through slits inthe supporting member 36 and maybe secured firmly in position by any suitable means. 'It has been found, for example, that'these contacts may be held firmly in position merelyby the tightness of thefit'between the contacts and the supporting member'36. Thecontacts 35 preferably include ears '35a-extending laterally therefrom and engaging one surface of the supporting member for stability. The rotatable contacts are, of course, so located with respect to the stationary contacts .21.that the tips of the rotatable contacts pass between the leaves of the stationary contacts 21 as the supporting member 36 rotates within the cup-shaped member 20.

Where knife switch contacts are employed,itiis, of course, essential that the desired relative positions of two cooperable contacts ,be accuratelymaintained, particularly in'the radialdirection, in a. rotating switch, since otherwise .themale contact vof a.pair ofcontacts might fail to pass betweenthe twovleaves ofthe corresponding female contact. .It .will benotedthat when one of the contact supporting elements, forzexample the member 36,

is preventedfrom moving radially .with respect to the other contact supporting .element 20 by .direct .engagement of the twovcontact supporting elements, there ,is substantially nopossibilityof radial misalignment ofthe cooperating contactsas long aszthe proper engagement between the two contact supportingelements is maintained.

It will be immediately .obvious upon inspection -,of the drawings that the contact supporting member 36 is very securely held in its proper radial position, as well as in its proper axial position, by the engagement of its peripheral edge with the rugged and simple metallic cup-shaped member 20-which directly supports the stationary contacts. This .is believed :to be a substantial improvement over the conventional switch; in which the relative position, and in particular the relative radial position, of the contact supporting elements is dependent upon proper alignment and positioning-of a series of interconnecting members such as a drive shaft, bearings,

and various elements of a framework.

The memberjZO neednot, of course, be literally cup- .shaped, even to the extend of the member illustrated. Rather, the term cup-shaped lS 1I1aDt to.,convey the .thoughtthat thisrnember has. .por.tions.iutegral therewith or. attached thereto which extend axially from the con- ..tact supporting portion thereof to engage the periphery iQfiLhe othercontact-supportingmember.

.in the.drawings, each of the cup-shaped members .20

has a pair of ears 40 and 41, which are supported on a framework including base plates 42, screws 43, and spacers 44. The screws 43 extend the entire distance between the two base plates 42, and the spacers 44 are hollow tubes fitting over the screws 43 and extending between adjacent sections of the multiple switch. The screws 43 pass through the openings in the ears 4t) and 41 while the spacers 44, which are too large to pass through the openings in the ears, serve to space the switch sections at a predetermined distance from each other. The screw has a nut 45, which, when tightened, holds the entire assembly securely together as a unit.

An operating shaft 46 is provided which has a rectangular cross-section in the vicinity of the switch sections 13, 14 and 15. The shaft 46 extends through circular openings 47 in the cup-shaped members 20 and accordingly is freely rotatable with respect thereto. However, the contact supporting member 36'has a rectangular opening 36a therein, which snuglyengages the shaft 46 whereby rotation of the shaft causes rotation of the member 36 and hence of the rotatable contacts 35 in each of the switch sections.

Since the cup-shaped members are firmly supported by the frame of the switch including the base plates 42 and the screws 43, and since the contact supporting-elements 36 are radially positioned by their engagement with the cup-shaped members 30, it is not required that the shaft 46 be supported in bearings. In the interest of greater solidity of the unit the forward end of the shaft 46 is shown-supported by a bearing 48 secured to the forward base plate 42, but the rearward end of theshaft 46 terminates adjacent the last switch section 15 and is not supported by a bearing.

In the drawings, the rotating contacts 35 are shown connected by a series of coils 50 of differing predetermined inductance values. When the switch is rotated, these coils are selectively inserted, by way of example, in the circuits involving the tubes 1t 11, and 12 for changing the inductive characteristics thereof. A switch constructed in accordance with the invention may, however, be applied to many other purposes. For example, two of the movable contacts 35 may be short-circuited or other types of contacts might be employed such that the circuits involved may merely be opened and closed selectively as the switch is operated.

One of the most important single features of the switch is the direct contact between the relatively movable contact supports whereby their relative radial positions are positively maintained without reliance upon a series of interconnecting members which might include a drive shaft, bearings, and portions of a framework or base.

Since one of the contact supporting members, namely the cup-shaped member 20 in the embodiment described, must extend an appreciable distance axially to engage the periphery of the other contact supporting member 36, it is desirable that the memberlt) be of substantial'rigidity and strength. in order that the radial alignment of these two members may be maintained accurately. For this reason the member 20 is preferably constructed of a metal and is, therefore, electrically conducting.

Each of the sheets 26 may support only one contact 21 or may be made to support a plurality of contacts as in the illustrated embodiment where two stationary contacts are arranged on each of two of the sheets 26. It isdesirable, however, that the plane of the faces of the contacts21 supported by the sheets 26 lie tangent to the circular path of the mating contacts 35 at the point along that path at which the contacts engage. If this isnot the case the contacts tendto deteriorate rapidly with use. Also, with this arrangement, the thrust transmitted from the rotatablecontacts to the stationary contacts, and hencetothe. sheets 26, ,as the switch is rotated, lies along a line parallel to and substantially coincidental with the plane of the corresponding sheets 26. As a result there is little tendency for this thrust to work the sheets 26 loose from the member 20.

This method and construction for mounting the stationary contacts on the electrically conducting member 20 have been found to be very economical, and at the same time secure the contacts very accurately and reliably in position. The method and apparatus are particularly adapted to a switch constructed in accordance with the invention as will now be apparent. However, the method and apparatus referred to are not limited to this particular application, but may be employed to advantage in many other situations.

Another embodiment of the invention is shown in Figs. 8 and 9 in which slots 52 are spaced from the opening 22' extending through the stationary contact support 20'. Sheets 26 of insulating material extend through the respective slots and are clamped therein by deformation of the member 20 as by punch marks or chisel marks 30'. Each sheet 26 extends part way across the opening 22' and has a contact 21' mounted thereon.

This mounting arrangement is particularly desirable in the application of the switch shown in the drawings where it is desired to close contacts which are angularly displaced from each other. It will be noted in Fig. 2 that each of the stationary contacts 21 is arranged on a supporting sheet 26 which is tangent to the circular path of the mating movable contact at a point slightly removed from the point of engagement of the mating contacts. In the embodiment shown in Figs. 8 and 9 the sheets 26' supporting the contacts 21 may be made tangent to the path of the movable contacts exactly at the point of engagement of the mating contacts. The embodiment shown in Figs. 1-7 has on the other hand the advantage of greater rigidity and simplicity.

While particular embodiments of the invention have been shown, it will be understood, of course, that the invention is not limited thereto since many modifications may be made, and it is, therefore, contemplated to cover by the appended claims any such modifications as fall within the true spirit and scope of the invention.

The invention having thus been described, what is claimed and desired to be secured by Letters Patent is:

l. A rotary electric switch comprising, a cup-shaped member, a substantially circular sheet-like member rotatable with respect to said cup-shaped member and adapted to fit within the lip of said latter member and to be guided thereby, means for causing relative rotation of said two members about an axis substantially perpendicular to the plane of said circular member said means comprising a rod-like element extending through said members and being freely movable longitudinally of itself with respect to said members, a plurality of switch contacts mounted on said circular member, and a plurality of switch contacts mounted on said cup-shaped member, said first-mentioned contacts being selectively cooperable with said last mentioned contacts as said two members are rotated with respect to each other.

2. A rotary electric switch comprising a cup-shaped member having a recessed flange, a substantially circular sheet-like member rotatable with respect to said cupshaped member and adapted to fit within said recessed flange and to be guided thereby, means for causing relative rotation of said two members, a plurality of knife switch contacts mounted on said circular member and extending toward said cup-shaped member, an opening through said cup-shaped member and a pair of aligned slots extending through said plate and communicating with said opening, a sheet of insulating material having two edges extending through said slots and fitting snugly therein, said cup-shaped member being deformed adjacent the edges of said slots to squeeze said sheet therein, thereby locking said sheet in a fixed position with respect to said member, and a switch contact secured to said sheet and extending through said opening in said cup-shaped member in spaced relationship to the edges of said member adjacent said opening, said last-mentioned contact extending toward said circular member and being selectably cooperable with said first-mentioned contacts as said two members are rotated with respect to each other.

3. The elements of claim 2 in which said sheet of insulating material is substantially flat and the plane of said sheet lies substantially parallel to the axis of relative rotation of said two members and substantially tangent to the path of relative motion of said contacts mounted on said circular member at the point of engagement of said contacts with said contact secured to said sheet.

4. A rotary electric switch comprising a cup-shaped member having a recessed flange, a substantially circular sheet-like member rotatable with respect to said cupshaped member and adapted to fit within said recessed flange and to be guided thereby, means for causing relative rotation of said two members, a plurality of knife switch contacts mounted on said circular member and extending toward said cup-shaped member, an opening through said cup-shaped member and a pair of aligned slots extending through said plate and communicating with said opening, a sheet of insulating material having two edges extending through said slots and fitting snugly therein, said sheet also having a pair of cars extending laterally and outwardly of said edges, said ears forming shoulders engaging said cup-shaped member beyond the ends of said slots, said cup-shaped member being deformed adjacent the edges of said slots to squeeze said sheet therein, thereby locking said sheet in a fixed position with respect to said member, and a switch contact secured to said sheet and extending through said opening in said cup-shaped member in spaced relationship to the edges of said member adjacent said opening, said last-mentioned contact extending toward said circular member and being selectively cooperable with said firstmentioned contacts as said two members are rotated with respect to each other.

5. The elements of claim 4 in which said sheet of insulating material is substantially flat and the plane of said sheet lies substantially parallel to the axis of relative rotation of said two members and substantially tangent to the path of relative motion of said contacts mounted on said circular member at the point of engagement of said contacts with said contact secured to said sheet.

6. A rotary electiric switch including a substantially circular contact supporting member, a contact supporting member adjacent said circular member, means for causing relative rotational movement of said two members, said second-mentioned member having means engaging the periphery of said circular member for preventing radial movement and axial movement of said circular member with respect to said second-mentioned member.

7. A rotary electric switch comprising a substantially circular contact supporting member, a contact supporting member adjacent said circular member, means for causing relative rotation of said two members, said second-mentioned member having means receiving the peripheral edge of said circular member and restraining said circular member from axial movement with respect to said second mentioned member.

8. A rotary electric switch comprising a substantially circular contact supporting member, a cup-shaped contact supporting member adjacent said circular member, means for causing relative rotation of said two members, said cup-shaped member having means adjacent the lip thereof for receiving the peripheral edge of said circular member and restraining said circular member from radial movement and axial movement with respect to said i Refereuces (Eitedin the file- 'Of thisatent 'IUNITED STATES QPATENTS Christie -Me 1y 15, 1928 8 ,Shelley Dec. 12, 1932 Hall -May 5, 1936 Watts Nov. 2, 1937 Knauf '=Mar. 15, 1949 Malhiot ''Feb. 7, 1950 Minneci July 4, 1950 Hilsinger Nov. 27,1951 

